MicroRNA-224 is involved in transforming growth factor-beta-mediated mouse granulosa cell proliferation and granulosa cell function by targeting Smad4

Interaction of circulating TGFβ regulatory miRNAs in different severity of diabetic kidney disease

AIMS

To explore the interaction of TGFβ regulatory microRNAs (miRNAs) with different severities of diabetic kidney disease (DKD).

METHODS

According to different UACR (30 and 300 mg/g), 436 subjects were included, and high glucose induced RMCs were cultured. Real-time PCR, ELISA, and automatic biochemical analysis were used to measure miRNAs, TGFβ1, and other biochemical indicators in serum and RMCs. Target genes of miRNA were predicted and visualised by bioinformatics.

RESULTS

HbA1c, TGFβ1, miR-217, and miR-224 in T2DM patients increased with UACR, while miR-192 and miR-216a decreased. Ln UACR was positively correlated with HbA1c, TGFβ1, miR-217, and miR-224, and negatively correlated with miR-192 and miR-216a. High glucose and TGFβ1 affected miRNAs and these miRNAs affected each other. The miRNA target genes mainly revolve around PTEN, PI3K/Akt, and MAPK signalling pathways.

CONCLUSION

TGFβ regulatory miRNAs and different severity of DKD have a potential interaction regulating fibrosis through PTEN, PI3K/Akt, and MAPK pathways.

Granulosa Cells-Related MicroRNAs in Ovarian Diseases: Mechanism, Facts and Perspectives

MicroRNAs (miRNAs) are a class of short single-stranded, noncoding RNAs that affect the translation of mRNAs by imperfectly binding to homologous 3'UTRs. Research on miRNAs in ovarian diseases is constantly expanding because miRNAs are powerful regulators of gene expression and cellular processes and are promising biomarkers. miRNA mimics, miRNA inhibitors and molecules targeting miRNAs (antimiRs) have shown promise as novel therapeutic agents in preclinical development. Granulosa cells (GCs) are supporting cells for developing oocytes in the ovary. GCs regulate female reproductive health by producing sex hormones and LH receptors. Increasing research has reported the relevance of miRNAs in GC pathophysiology. With in-depth studies of disease mechanisms, there are an increasing number of studies on the biomolecular pathways of miRNAs in gynecology and endocrinology. In the present review, we summarize the different functions of GC-related microRNAs in various ovarian disorders, such as polycystic ovary syndrome, premature ovarian insufficiency, premature ovarian failure and ovarian granulosa cell tumors.

Function of MicroRNAs in Normal and Abnormal Ovarian Activities: A Review Focus on MicroRNA-21

Some failures in ovary function, like folliculogenesis and oogenesis, can give rise to various infertility-associated problems, including polycystic ovary syndrome (PCOS) and premature ovarian insufficiency (POI). PCOS influences 8 to 20% of women; while POI occurs in at least 1% of all women. Regrettably, the current therapies for these diseases have not sufficiently been effective, and finding a suitable strategy is still a puzzle. One of the helpful strategies for managing and treating these disorders is understanding the contributing pathogenesis and mechanisms. Recently, it has been declared that abnormal expression of microRNAs (miRNAs), as a subset of non-coding RNAs, is involved in the pathogenesis of reproductive diseases. Among the miRNAs, the roles of miRNA-21 in the pathogenesis of PCOS and POI have been highlighted in some documents; hence, the purpose of this mini-review was to summarize the evidences in conjunction with the functions of this miRNA and other effective microRNAs in the normal or abnormal functions of the ovary (i.e., PCOS and POI) with a mechanistic insight.

[Genetic factors in degenerative disc disease]

OBJECTIVE

To analyze available literature data on the role of genetic factors in degenerative disc disease.

METHODOLOGY

We reviewed the PubMed, MEDLINE, Cohrane Library, e-Library databases using the following keywords: degenerative spine lesions, intervertebral disc herniation, pathogenesis, genetic regulation.

RESULTS

Searching depth was 2002-2022. We reviewed 84 references. Exclusion criteria: duplicate publications, reviews without detailed description of results, opinions. Finally, we included 43 the most significant studies.

CONCLUSION

There are literature data on proinflammatory cytokines, growth factors and osteodestructive processes in pathogenesis of degenerative disc disease. However, there is only fragmentary information about the role of genetic regulation of these processes. Some factors, such as microRNA, TGF-b, VEGF, MMP are still poorly understood.

miR-138-5p promotes chicken granulosa cell apoptosis via targeting SIRT1

Granulosa cell (GC) apoptosis is the main trigger of follicular atresia. MicroRNAs (miRNAs) are 18-22 nt RNAs whose function is primarily determined by their extended seed region and are considered to be involved in the biological functions of follicular development, including follicular atresia, folliculogenesis, and oogenesis. MiR-138-5p is known to act on chicken GCs. In this study, we found that miR-138-5p was enriched in reproductive organs, such as the uterus and ovaries. To examine whether miR-138-5p could regulate the biological process of GCs, miR-138-5p was examined by transfection of cells with a mimic or inhibitor of miR-138-5p. Expression levels of caspase-3 and caspase-9 mRNA and protein were markedly increased or decreased after transfection of the mimic or inhibitor, respectively. Furthermore, following miR-138-5p inhibition, SIRT1, one of the target genes of miR-138-5p, was found to increase the mRNA, which is correlated with the increased levels of BCL2 expression, an anti-apoptotic gene in the chicken GCs. These results suggest that miR-138-5p promotes apoptosis in chicken GCs by targeting SIRT1.

MicroRNA-338-3p helps regulate ovarian function by affecting granulosa cell function and early follicular development

BACKGROUND

Follicular development in mammalian ovaries is a complex and dynamic process, and the interactions and regulatory-feedback loop between the follicular microenvironment, granulosa cells (GCs), and oocytes can affect follicular development and normal ovary functions. Abnormalities in any part of the process may cause abnormal follicular development, resulting in infertility. Hence, exploring the pathogenesis of abnormal follicular development is extremely important for diagnosing and treating infertile women.

METHODS

RNA sequencing was performed with ovarian cortical tissues established in vitro. In situ-hybridization assays were performed to study microRNA-338-3p (miR-338-3p) expressed in GCs and oocytes. In vitro culture models were established with GCs and neonatal mouse ovaries to study the biological effects of miR-338-3p. We also performed in vivo experiments by injecting adeno-associated virus vectors that drive miR-338-3p overexpression into the mouse ovarian bursae.

RESULTS

Sequencing analysis showed that miR-338-3p was expressed at significantly higher levels in ovarian cortical tissues derived from patients with ovarian insufficiency than in cortical tissues derived from patients with normal ovarian function; miR-338-3p was also significantly highly expressed in the GCs of patients with diminished ovarian reserve (P < 0.05). In situ-hybridization assays revealed that miR-338-3p was expressed in the cytoplasm of GCs and oocytes. Using in vitro culture models of granulosa cells, we found that miR-338-3p overexpression significantly suppressed the proliferation and oestradiol-production capacity of GCs (P < 0.05). In vitro culture models of neonatal mouse ovaries indicated that miR-338-3p overexpression suppressed the early follicular development in mouse ovaries. Further analysis revealed that miR-338-3p might be involved in transforming growth factor β-dependent regulation of granulosa cell proliferation and, thus, early follicular development. Injecting miR-338-3p-overexpression vectors into the mouse ovarian bursae showed that miR-338-3p down-regulated the oocyte mitochondrial membrane potential in mice and disrupted mouse oestrous cycles.

CONCLUSION

miR-338-3p can affect early follicular development and normal ovary functions by interfering with the proliferation and oestradiol production of GCs. We systematically elucidated the regulatory effect of miR-338-3p on follicular development and the underlying mechanism, which can inspire new studies on the diagnosis and treatment of diseases associated with follicular development abnormalities.

Different types of bisphenols alter ovarian steroidogenesis: Special attention to BPA

Endocrine disruptors such as bisphenol A (BPA) and some of its analogues, including BPS, BPAF, and BPE, are used extensively in the manufacture of plastics. These synthetic chemicals could seriously alter the functionality of the female reproductive system. Although the number of studies conducted on other types of bisphenols is smaller than the number of studies on BPA, the purpose of this review study was to evaluate the effects of bisphenol compounds, particularly BPA, on hormone production and on genes involved in ovarian steroidogenesis in both in vitro (human and animal cell lines) and in vivo (animal models) studies. The current data show that exposure to bisphenol compounds has adverse effects on ovarian steroidogenesis. For example, BPA, BPS, and BPAF can alter the normal function of the hypothalamic-pituitary-gonadal (HPG) axis by targeting kisspeptin neurons involved in steroid feedback signals to gonadotropin-releasing hormone (GnRH) cells, resulting in abnormal production of LH and FSH. Exposure to BPA, BPS, BPF, and BPB had adverse effects on the release of some hormones, namely 17-β-estradiol (E2), progesterone (P4), and testosterone (T). BPA, BPE, BPS, BPF, and BPAF are also capable of negatively altering the transcription of a number of genes involved in ovarian steroidogenesis, such as the steroidogenic acute regulatory protein (StAR, involved in the transfer of cholesterol from the outer to the inner mitochondrial membrane, where the steroidogenesis process begins), cytochrome P450 family 17 subfamily A member 1 (Cyp17a1, which is involved in the biosynthesis of androgens such as testosterone), 3 beta-hydroxysteroid dehydrogenase enzyme (3β-HSD, involved in the biosynthesis of P4), and cytochrome P450 family 19 subfamily A member 1 (Cyp19a1, involved in the biosynthesis of E2). Exposure to BPA, BPB, BPF, and BPS at prenatal or prepubertal stages could decrease the number of antral follicles by activating apoptosis and autophagy pathways, resulting in decreased production of E2 and P4 by granulosa cells (GCs) and theca cells (TCs), respectively. BPA and BPS impair ovarian steroidogenesis by reducing the function of some important cell receptors such as estrogens (ERs, including ERα and ERβ), progesterone (PgR), the orphan estrogen receptor gamma (ERRγ), the androgen receptor (AR), the G protein-coupled estrogen receptor (GPER), the FSHR (follicle-stimulating hormone receptor), and the LHCGR (luteinizing hormone/choriogonadotropin receptor). In animal models, the effects of bisphenol compounds depend on the type of animals, their age, and the duration and dose of bisphenols, while in cell line studies the duration and doses of bisphenols are the matter.

Two single nucleotide variants in the miR-23a promoter affect granulosa cell apoptosis

microRNAs (miRNAs) are well known to be important in mammalian female fertility. However, the genetic regulation of miRNAs associated with female fertility remains largely unknown. Here, we report that two single-nucleotide variants (SNVs) in the miR-23a promoter strongly influence miR-23a transcription and function in granulosa cell (GC) apoptosis. Two novel SNVs, g.-283G>C and g.-271C>T, were detected in the porcine miR-23a promoter by pooled-DNA sequencing. Furthermore, SNVs in the promoter region influenced miR-23a transcription in porcine GCs by altering its promoter activity. Functionally, SNVs in the promoter strongly influenced miR-23a regulation of early apoptosis in porcine GCs cultured in vitro. In addition, a preliminary association analysis showed that the combined genotypes of the two SNVs, rather than a single SNV, were tentatively associated with sow fertility traits in a Large White population. Overall, our findings suggest that the SNVs g.-283G>C and g.-271C>T in the miR-23a promoter are causal variants affecting GC apoptosis and miR-23a may be a potential small-molecule nonhormonal drug for regulating female fertility.

Exosomes: The role in mammalian reproductive regulation and pregnancy-related diseases

Exosomes are a kind of extracellular vesicles that are produced and secreted by different mammalian cells. They serve as cargo proteins and can transfer different kinds of biomolecules, including proteins, lipids, and nucleic acids, which consequently act on target cells to exert different biological effects. Recent years have witnessed a significant increase in the number of studies on exosomes due to the potential effects of exosomes in the diagnosis and treatment of cancers, neurodegenerative diseases, and immune disorders. Previous studies have demonstrated that exosomal contents, especially miRNAs, are implicated in numerous physiological processes such as reproduction, and are crucial regulators of mammalian reproduction and pregnancy-related diseases. Here, we describe the origin, composition, and intercellular communication of exosomes, and discuss their functions in follicular development, early embryonic development, embryonic implantation, male reproduction and development of pregnancy-related diseases in humans and animals. We believe this study will provide a foundation for revealing the mechanism of exosomes in regulating mammalian reproduction, and providing new approaches and ideas for the diagnosis and treatment of pregnancy-related diseases.

Role of miRNAs interference on ovarian functions and premature ovarian failure

Premature ovarian failure is a to some extent unknown and intricate problem with diverse causes and clinical manifestations. The lack of ovarian sex hormones presumably is effective in the occurrence of ovarian failure. Our progress in this field has been very little despite undertaken scientific research endeavors; scholars still are trying to understand the explanation of this dilemmatic medical condition. In contrast, the practice of clinical medicine has made meaningful strides in providing assurance to the women with premature ovarian insufficiency that their quality of life as well as long-term health can be optimized through timely intervention. Very recently Scientists have investigated the regulating effects of small RNA molecules on steroidogenesis apoptosis, ovulation, gonadal, and corpus luteum development of ovaries. In this literature review, we tried to talk over the mechanisms of miRNAs in regulating gene expression after transcription in the ovary. Video abstract.

Why Is It So Difficult To Have Competent Oocytes from In vitro Cultured Preantral Follicles?

The developmental competence of oocytes is acquired gradually during follicular development, mainly through oocyte accumulation of RNA molecules and proteins that will be used during fertilization and early embryonic development. Several attempts to develop in vitro culture systems to support preantral follicle development up to maturation are reported in the literature, but oocyte competence has not yet been achieved in human and domestic animals. The difficulties to have fertilizable oocytes are related to thousands of mRNAs and proteins that need to be synthesized, long-term duration of follicular development, size of preovulatory follicles, composition of in vitro culture medium, and the need of multi-step culture systems. The development of a culture system that maintains bidirectional communication between the oocyte and granulosa cells and that meets the metabolic demands of each stage of follicle growth is the key to sustain an extended culture period. This review discusses the physiological and molecular mechanisms that determine acquisition of oocyte competence in vitro, like oocyte transcriptional activity, follicle and oocyte sizes, and length and regulation of follicular development in murine, human, and domestic animal species. The state of art of in vitro follicular development and the challenges to have complete follicular development in vitro are also highlighted.

Integrated analysis of miRNA and mRNA expression profiles in testes of Landrace and Hezuo boars

Precocious puberty is closely related to testicular development and spermatogenesis, and there is increasing evidence that miRNAs are involved in regulation of testicular development and spermatogenesis. However, little is known about the regulation of microRNAs (miRNAs) during precocious maturation in Hezuo (HZ) boars. In this study, serum Testosterone (T), Estradiol (E₂), Follicle-stimulating hormone (FSH) and Luteinizing hormone (LH) levels were detected in HZ and Landrace (LC) boars in the postnatal period at 30, 90, 120, 180, and 240 days, and the testes of HZ and LC boars at 30 and 120 days were used for histological observation. In addition, we performed small RNA-Seq to identify miRNA at sexual immaturity (30-days-old) and maturity (120-days-old) of HZ boar testis (using LC boar as control) to reveal the key miRNA in regulation of precocious puberty. Hormone assay results showed that high levels of T, E₂, FSH, and LH may be related to precocious sexual maturity of HZ boars, and that FSH may play an important function before sexual maturity. Histological observation showed that HZ boars developed earlier than LC boars and had reached sexual maturity at 120 days. Small RNA-Seq yielded a total of 359 exist miRNAs, 767 known miRNAs and 322 novel miRNAs in 12 samples; 549, 468, 133, and 247 differentially expressed (DE) miRNAs were identified between Ha vs. Hb, La vs. Lb, Ha vs. La, and Hb vs. Lb (log₂ fold change >1 and p < 0.05). Enrichment analysis showed that target genes of these DE miRNAs were enriched in many gene ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathways (such as PI3K-Akt, Hippo and Rap1 signaling pathways) were related to testicular development and spermatogenesis. Further screening, some miRNAs (such as ssc-miR-29b, ssc-miR-199b, ssc-miR-383, ssc-miR-149, ssc-miR-615, and ssc-miR-370) were possibly associated with precocious puberty. These results provide new light on miRNA regulatory mechanisms involved in precocious puberty.

miR-1306 induces cell apoptosis by targeting BMPR1B gene in the ovine granulosa cells

Bone morphogenetic protein receptor type-1B (BMPR1B) is one of the major gene for sheep prolificacy. However, few studies investigated its regulatory region. In this study, we reported that miR-1306 is a direct inhibitor of BMPR1B gene in the ovine granulosa cells (ovine GCs). We detected a miRNA response element of miR-1306 in the 3’ untranslated region of the ovine BMPR1B gene. Luciferase assay showed that the ovine BMPR1B gene is a direct target of miR-1306. qPCR and western blotting revealed that miR-1306 reduces the expression of BMPR1B mRNA and protein in the ovine granulosa cells. Furthermore, miR-1306 promoted cell apoptosis by suppressing BMPR1B expression in the ovine granulosa cells. Overall, our results suggest that miR-1306 is an epigenetic regulator of BMPR1B, and may serve as a potential target to improve the fecundity of sheep.

Identification of miR-34-3p as a candidate follicular phase serum marker for endometriosis: a pilot study

OBJECTIVE

To identify early follicular phase microribonucleic acids (miRNAs) that are altered in serum of women with endometriosis.

DESIGN

Case-control study.

SETTING

Large university-affiliated in vitro fertilization center.

PATIENT(S)

Women with (n = 21) and without (n = 24) endometriosis.

INTERVENTION(S)

Serum samples were obtained from laparoscopy-confirmed patients with endometriosis.

MAIN OUTCOME MEASURE(S)

The differential expression of serum miRNAs relative to controls was measured using the NanoString nCounter technology and validated by quantitative real-time polymerase chain reaction in an independent cohort of 27 patients with endometriosis and controls (n = 24). Microribonucleic acid target signaling pathways and genes were analyzed bioinformatically. A chemically modified stable miR-34-3p oligonucleotide was used to examine the effect on proliferation of VK2E6/E7 endometrial cells in vitro.

RESULT(S)

Eighteen miRNAs were significantly up-regulated, and 1 miRNA (hsa-miR-34c-3p) was significantly down-regulated in the follicular phase of patients with endometriosis. The analysis of target signaling pathways using TargetScan predicted regulation of the mitogen-activated protein kinase, phosphoinositide 3-kinase/protein kinase B, Hippo, adenosine monophosphate-activated protein kinase, transforming growth factor beta, and endometrial cancer pathways, which have been implicated in the pathogenesis of endometriosis, by these miRNAs. The analysis of sequence complementarity identified prostaglandin E2 receptor 4, interleukin 6 signal transducer, and polo-like kinase 4 genes as possible direct targets of hsa-miR-34-3p. DSDI-1, a chemically modified stable miR-34-3p oligonucleotide, reduced cell proliferation in VK2E6/E7 endometrial cells in vitro.

CONCLUSION(S)

The follicular phase miRNA levels are altered in serum of women with endometriosis and may be useful as reproducible detection biomarkers for early diagnosis of endometriosis. hsa-miR-34-3p is significantly down-regulated in endometriosis, targets endometriosis genes, and reduces endometrial cell proliferation in vitro. These results support hsa-miR-34-3p as a potential therapeutic target in endometriosis.

MiR-383-5p promotes apoptosis of ovarian granulosa cells by targeting CIRP through the PI3K/AKT signaling pathway

PURPOSE

To detect miR-383-5p and cold-inducible RNA binding protein (CIRBP, CIRP) expression in patients with polycystic ovary syndrome (PCOS) and explore the mechanism underlying their effect on apoptosis in ovarian granulosa cells (GCs).

METHODS

GCs were extracted from follicular fluid from 101 patients. MiR-383-5p and CIRP expression were assessed by quantitative real time polymerase chain reaction analysis. Correlation between them was assessed by Spearman correlation analysis. The potential of using miR-383-5p expression for discriminating PCOS and non-PCOS patients was predicted by receiver operating characteristic curve analysis. Proliferation and apoptosis of KGN cells transfected for miR-383-5p overexpression or knockdown was evaluated using cell counting kit-8 assay, flow cytometry, and western blot analysis. CIRP was identified as a direct target of miR-383-5p, and verified by dual-luciferase reporter assay.

RESULTS

The expression level of miR-383-5p was decreased and CIRP mRNA was increased in PCOS patients. The expression of miR-383-5p was correlated negatively with body-mass index, basal luteinizing hormone and testosterone levels, luteinizing hormone/follicle-stimulating hormone ratio, and the number of retrieved and metaphase II oocytes. MiR-383-5p had sufficient potential for prediction of PCOS. There was a negative correlation between the expression of miR-383-5p and CIRP. Overexpression of miR-383-5p enhanced the apoptosis of KGN cells. CIRP reversed the effect of miR-383-5p on promotion of apoptosis. MiR-383-5p mimics could suppress the PI3K/AKT signaling pathway, which was activated by the CIRP overexpressing plasmid.

CONCLUSIONS

MiR-383-5p promoted apoptosis of ovarian GCs through the PI3K/AKT signaling pathway by targeting CIRP.

Kisspeptin-10 Promotes Progesterone Synthesis in Bovine Ovarian Granulosa Cells via Downregulation of microRNA-1246

The objective of this study was to clarify the effect of kisspeptin-10 (kp-10) on the synthesis of progesterone (P4) in bovine granulosa cells (BGCs) and its mechanisms via microRNA 1246 (miR-1246). According to the results, we found that treating with kp-10 for 24 h could increase P4 level, the mRNA expression of the steroidogenesis-related gene steroidogenic acute regulatory protein (StAR), free cholesterol content, and decrease miR-1246 expression in BGCs. Overexpression of miR-1246 significantly inhibited P4 synthesis, StAR mRNA expression, and free cholesterol content in BGCs, whereas underexpression of miR-1246 significantly reversed this effect in BGCs. Additionally, overexpression of miR-1246 counteracted the accelerative effect of kp-10 on P4 synthesis, StAR mRNA expression, and free cholesterol content in BGCs. Conversely, underexpression of miR-1246 enhanced the accelerative effect of kp-10 on P4 synthesis, StAR mRNA expression, and free cholesterol content in BGCs. Meanwhile, results of dual-luciferase reporter assays indicated that miR-1246 targeted the 3′UTR of StAR in BGCs. These results demonstrated that kp-10 induced P4 synthesis in BGCs by promoting free cholesterol transport via regulating expression of miR-1246/StAR.

A Concise Review of MicroRNA-383: Exploring the Insights of Its Function in Tumorigenesis

MicroRNAs (miRNAs) are small noncoding RNAs that commonly have 18-22 nucleotides and play important roles in the regulation of gene expression via directly binding to the 3'-UTR of target mRNAs. Approximately 50% of human genes are regulated by miRNAs and they are involved in many human diseases, including various types of cancers. Recently, microRNA-383 (miR-383) has been identified as being aberrantly expressed in multiple cancers, such as malignant melanoma, colorectal cancer, hepatocellular cancer, and glioma. Increasing evidence suggests that miR-383 participates in tumorigenic events including proliferation, apoptosis, invasion, and metastasis as well as drug resistance. Although downstream targets including CCND1, LDHA, VEGF, and IGF are illustrated to be regulated by miR-383, its roles in carcinogenesis are still ambiguous and the underlying mechanisms are still unclear. Herein, we review the latest studies on miR-383 and summarize its functions in human cancers and other diseases. The goal of this review is to provide new strategies for targeted therapy and further investigations.

Transcriptome Analysis Reveals Key miRNA-mRNA Pathways in Ovarian Tissues of Yunshang Black Goats With Different Kidding Numbers

The granulosa cell (GC) is the basic functional unit of follicles, and it is important for promoting follicle growth and sex hormones, as well as growth factor secretion in the process of reproduction. A variety of factors influence granulocyte proliferation, yet there are still many gaps to be filled in target and non-coding RNA regulation. In our study, the differentially expressed (DE) mRNAs and miRNAs were detected by using RNA-seq, and we constructed a mRNA-miRNA network related to goat prolificacy. Then, the goat primary GCs were isolated from the follicle for the function validation of candidate genes and their regulator miRNAs. A total of 2,968 DE mRNAs and 99 DE miRNAs were identified in the high- and low-prolificacy goat by RNA-seq, of which there were 1,553 upregulated and 1,415 downregulated mRNAs, and 80 upregulated and 19 downregulated miRNAs, respectively. JAK3 was identified as highly expressed in the low-prolificacy goats (3 times higher than high-prolificacy goats), and the integrated analysis showed that chi-miR-493-3p was a potential regulator of JAK3. The analysis of Kyoto Encyclopedia of Genes and Genomes (KEGG) showed that JAK3 was involved in the PI3K-Akt signaling pathway, the Jak-STAT signaling pathway, and signaling pathways regulating pluripotency of stem cells. In particular, the PI3K-Akt signaling pathway was a typical pathway for cell proliferation, differentiation, apoptosis, and migration. We found that the chi-miR-493-3p targets JAK3 directly via RT-qPCR, dual fluorescence assays, and Western blot. Furthermore, the expression of JAK3 was significantly decreased by the chi-miR-493-3p mimic and increased by the chi-miR-493-3p inhibitor. The CCK-8 assay showed that overexpression of JAK3 promoted cell proliferation, while inhibiting JAK3 had the opposite effect. The expression of cell proliferation markers CDK4 and cyclin D2 also showed the same results. Moreover, the enzyme-linked immunosorbent assay showed that steroid hormones E₂ and PROG were increased by overexpressing JAK3 and decreased by inhibiting JAK3. Therefore, our results identified a chi-miR-439-3p-JAK3 regulatory pathway, which provided a new insight into the GC proliferation and prolificacy of goat.

MicroRNAs in Dopamine Agonist-Resistant Prolactinoma

Dopamine agonists (DAs) are preferred for the treatment of prolactinomas and are usually very effective. Nonetheless, 20-30% of bromocriptine- and approximately 10% of cabergoline-treated individuals exhibit resistance to DAs. In addition, the mechanism underlying this phenomenon remains elusive. In this study, we summarize the major findings regarding the role of microRNAs (miRNAs) in the pathogenesis of DA-resistant prolactinoma (DARP). Currently available evidence suggests that miRNAs are usually dysregulated in DARP and that, although controversial, the dysregulated miRNAs target the transforming growth factor (TGF)-β, dopamine 2 receptor (D2R), or estradiol (E2)/estrogen receptor (ER) signaling pathways to mediate the therapeutic effect of DAs. These findings provide new incentives for research on innovative strategies for predicting patients' responsiveness to dopamine therapies and for developing treatment approaches. Unfortunately, recent studies tended to focus exclusively on the differential miRNA expression profiles between DARP and dopamine-sensitive prolactinoma, and no definitive consensus has been reached regarding the role of these miRNAs in the modulation mechanism. Therefore, current and future efforts should be directed toward the exploration of the mechanism underlying the dysregulation of miRNAs as well as of the target proteins that are affected by the dysregulated miRNAs. Furthermore, the modulation of the expression of dysregulated miRNAs, which target the D2R, TGF-β, or E2/ER signaling pathways, might be a promising alternative to treat patients with DARP and improve their prognosis.

Roles of Noncoding RNA in Reproduction

The World Health Organization predicts that infertility will be the third major health threat after cancer and cardiovascular disease, and will become a hot topic in medical research. Studies have shown that epigenetic changes are an important component of gametogenesis and related reproductive diseases. Epigenetic regulation of noncoding RNA (ncRNA) is appropriate and is a research hotspot in the biomedical field; these include long noncoding RNA (lncRNA), microRNA (miRNA), and PIWI-interacting RNA (piRNA). As vital members of the intracellular gene regulatory network, they affect various life activities of cells. LncRNA functions as a molecular bait, molecular signal and molecular scaffold in the body through molecular guidance. miRNAs are critical regulators of gene expression; they mainly control the stability or translation of their target mRNA after transcription. piRNA functions mainly through silencing genomic transposable elements and the post-transcriptional regulation of mRNAs in animal germ cells. Current studies have shown that these ncRNAs also play significant roles in the reproductive system and are involved in the regulation of essential cellular events in spermatogenesis and follicular development. The abnormal expression of ncRNA is closely linked to testicular germ cell tumors, poly cystic ovary syndrome and other diseases. This paper briefly presents the research on the reproductive process and reproductive diseases involving ncRNAs.

Therapeutic Mechanism and Clinical Observation of Traditional Chinese Medicine Combined with Interventional Recanalization for Tubal Infertility

To observe the clinical effect of traditional Chinese medicine (TCM) combined with interventional recanalization therapy in the treatment of tubal obstructive infertility, first, different treatment approaches were used on rabbits, and transmission electron microscopy (TEM) indicated that interventional recanalization combined with TCM can significantly ameliorate the pathological condition of the fallopian tube after treatment. Moreover, ELISA disclosed that the treatment could significantly reduce the levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) and increase the expression of interleukin-10 (IL-10), which demonstrated that TCM therapy can help against inflammation of the fallopian tubes. PCR array analysis revealed that BMP4, BMPR1A, SMAD2, SMAD3, SMAD4, and KLF10 expressions were upregulated, and SMAD7 expression was downregulated, proving that combined treatment could influence gene expression in the TGF-β family and further regulate the secretion of proteins in SMADs. In addition, a clinical study recorded the fallopian tube patency rate of 165 patients after 12 months. The recanalization rates in the two groups were 81.9% and 53.1%, with the higher rates in the combined medicine enema group. All these findings implied that interventional recanalization combined with TCM preparation has a stronger effect. The mechanism probably involves effects on the expression of genes in the TGF-β/SMAD and BMP/SMAD signaling pathways, with simultaneous regulation of inflammatory factors, thereby improving the ovarian environment and increasing pregnancy rates.

miR-2337 induces TGF-β1 production in granulosa cells by acting as an endogenous small activating RNA

Transforming growth factor-β1 (TGF-β1) is essential for ovarian function and female fertility in mammals. Herein, we identified three completely linked variants, including two known variants referred to as c.1583A > G and c.1587A > G and the novel variant c.2074A > C in the porcine TGF-β1 3′-UTR. An important role of these variants in Yorkshire sow fertility was revealed. Variants c.1583A > G and c.1587A > G were located at the miRNA response element (MRE) of miR-2337 and affected miR-2337 regulation of TGF-β1 3′-UTR activity. Interestingly, miR-2337 induces, not reduces the transcription and production of TGF-β1 in granulosa cells (GCs). Mechanistically, miR-2337 enhances TGF-β1 promoter activity via the MRE motif in the core promoter region and alters histone modifications, including H3K4me2, H3K4me3, H3K9me2, and H3K9ac. In addition, miR-2337 controls TGF-β1-mediated activity of the TGF-β signaling pathway and GC apoptosis. Taken together, our findings identify miR-2337 as an endogenous small activating RNA (saRNA) of TGF-β1 in GCs, while miR-2337 is identified as a small activator of the TGF-β signaling pathway which is expected to be a new target for rescuing GC apoptosis and treating low fertility.

Long Non-Coding RNA TRG-AS1 Promoted Proliferation and Invasion of Lung Cancer Cells Through the miR-224-5p/SMAD4 Axis

INTRODUCTION

The aim of this study was to investigate the role and mechanism of long non-coding RNA (lncRNA) TRG-AS1 in mediating the proliferation, invasion and migration of lung cancer cells as well lung tumor growth.

METHODS

Firstly, the expression levels of TRG-AS1, miR-224-5p in lung cancer tissues or cells were quantified by quantitative real-time PCR. Western blot analysis was conducted to measure the expression levels of protein SMAD4. CCK-8 assay, wound healing assay and transwell assay were conducted to evaluate cell proliferation, migration and invasion, respectively. The interaction between TRG-AS1 and miR-224-5p was predicted by bioinformatics analysis. Dual-luciferase assay and RNA pull-down assay were performed to further confirm their interaction. In addition, the interaction between miR-224-5p and SMAD4 was detected by RIP assay.

RESULTS

The results showed that TRG-AS1 was highly upregulated and miR-224-5p was downregulated in lung cancer. A negative correlation was found between TRG-AS1 and miR-224-5p. Furthermore, upregulation of TRG-AS1 promoted cell proliferation and invasion, while overexpression of miR-224-5p attenuated the effects of TRG-AS1. The downstream protein SMAD4 played an important role. In vivo study showed that knockdown of TRG-AS1 effectively retarded tumor growth.

DISCUSSION

Our data suggested that the TRG-AS1/miR-224-5p/SMAD4 axis may be a potential therapeutic target in lung cancer.

MicroRNA 195-5p Targets Foxo3 Promoter Region to Regulate Its Expression in Granulosa Cells

Forkhead box O3 (Foxo3) is a member of the FOXO subfamily within the forkhead box (FOX) family, which has been shown to be essential for ovarian follicular development and maturation. Previous studies have shown the abundant expression of miR-195-5p in the nuclei of porcine granulosa cells (GCs), suggesting its potential role during ovarian follicle growth. In this study, a conditional immortalized porcine granulosa cell (CIPGC) line was used to determine whether the expression of Foxo3 could be regulated by the nuclear-enriched miR-195-5p. Through silico target prediction, we identified a potential binding site of miR-195-5p within the Foxo3 promoter. The over-expression of miR-195-5p increased Foxo3 expression at both mRNA and protein levels, while the knockdown of miR-195-5p decreased the expression of Foxo3. Furthermore, driven by the Foxo3 promoter, luciferase reporter activity was increased in response to miR-195-5p, while the mutation of the miR-195-5p binding site in the promoter region abolished this effect. In addition, the siRNA knockdown of Argonaute (AGO) 2, but not AGO1, significantly decreased Foxo3 transcript level. However, miR-195-5p failed to upregulate Foxo3 expression when AGO2 was knocked down. Moreover, chromatin immunoprecipitation (CHIP) assay showed that anti-AGO2 antibody pulled down both AGO2 and the Foxo3 promoter sequence, suggesting that AGO2 may be required for miR-195-5p to regulate Foxo3 expression in the nucleus. Additionally, Foxo3 expression was significantly increased by valproic acid (VPA), the inhibitor of deacetylase, as well as by methyltransferase inhibitor BIX-01294, indicating the involvement of histone modification. These effects were further enhanced in the presence of miR-195-5p and were decreased when miR-195-5p was knocked down. Overall, our results suggest that nuclear-enriched miR-195-5p regulates Foxo3 expression, which may be associated with AGO2 recruitment, as well as histone demethylation and acetylation in ovarian granulosa cells.

miR-133b targets tagln2 and functions in tilapia oogenesis

microRNAs (miRNAs) are important components of non-coding RNAs that participate in diverse life activities by regulating gene expression at the post transcriptional level through base complementary pairing with 3'UTRs of target mRNAs. miR-133b is a member of the miR-133 family, which play important roles in muscle differentiation and tumorigenesis. Recently, miR-133b was reported to affect estrogen synthesis by targeting foxl2 in mouse, while its role in fish reproduction remains to be elucidated. In the present study, we isolated the complete sequence of miR-133b, which was highly expressed in tilapia ovary at 30 and 90 dah (days after hatching) and subsequently decreased at 120 to 150 dah by qPCR. Interestingly, only a few oogonia were remained in the antagomir-133b treated tilapia ovary, while phase I and II oocytes were observed in the ovaries of the control group. Unexpectedly, the expression of foxl2 and cyp19a1a, as well as estradiol levels in serum were increased in the treated group. Furthermore, tagln2, an important factor for oogenesis, was predicted as the target gene of miR-133b, which was confirmed by dual luciferase reporter vector experiments. miR-133b and tagln2 were co-expressed in tilapia ovaries. Taken together, miR-133b may be involved in the early oogenesis of tilapia by regulating tagln2 expression. This study enriches the understanding of miR-133b function during oogenesis and lays a foundation for further study of the regulatory network during oogenesis.

Modulation of Cathepsin S (CTSS) Regulates the Secretion of Progesterone and Estradiol, Proliferation, and Apoptosis of Ovarian Granulosa Cells in Rabbits

Simple Summary

In goat and sheep, CTSS is reported to be important for the development and maturation of oocytes by regulating cell proliferation and apoptosis. The purpose of this study was to investigate the role of CTSS in regulating cell apoptosis and hormone secretion in rabbit granulosa cells. Our results suggested that the CTSS gene can promote the proliferation of granulosa cells and reduce its apoptosis in vitro, while overexpression of CTSS promoted the secretion of progesterone and estrogen in rabbit granulosa cells. Therefore, manipulation of CTSS may improve development of oocytes, and thus provide an approach for better manipulation of rabbit reproductive performance.

Abstract

Cathepsin S (CTSS) is a member of cysteine protease family. Although many studies have demonstrated the vital role of CTSS in many physiological and pathological processes including tumor growth, angiogenesis and metastasis, the function of CTSS in the development of rabbit granulosa cells (GCS) remains unknown. To address this question, we isolated rabbit GCS and explored the regulatory function of the CTSS gene in cell proliferation and apoptosis. CTSS overexpression significantly promoted the secretion of progesterone (P4) and estrogen (E2) by increasing the expression of STAR and CYP19A1 (p < 0.05). We also found that overexpression of CTSS increased GCS proliferation by up-regulating the expression of proliferation related gene (PCNA) and anti-apoptotic gene (BCL2). Cell apoptosis was markedly decreased by CTSS activation (p < 0.05). In contrast, CTSS knockdown significantly decreased the secretion of P4 and E2 and the proliferation of rabbit GCS, while increasing the apoptosis of rabbit GCS. Taken together, our results highlight the important role of CTSS in regulating hormone secretion, cell proliferation, and apoptosis in rabbit GCS. These results might provide a basis for better understanding the molecular mechanism of rabbit reproduction.

Correlation of plasma exosomal microRNAs with the efficacy of immunotherapy in EGFR / ALK wild-type advanced non-small cell lung cancer

Background

Immunotherapy has become an important treatment option for patients with advanced non-small cell lung cancer (NSCLC). At present, none of these existing biomarkers can effectively stratify true responders and there is an urgent need for identifying novel biomarkers. Exosomes derived from the serum of patients with cancer have been proven to be reliable markers for cancer diagnosis. Here, we explored the possibility of using plasma-derived exosomal microRNAs as potential biomarkers for optimal selection of patients with advanced EGFR/ALK negative NSCLC to immunotherapy.

Methods

From June 2017 to February 2019, 30 patients with advanced EGFR/ALK wild-type (WT) NSCLC who received PD-1/PD-L1 inhibitors were enrolled. The efficacy evaluation was conducted after every three cycles of treatment according to RECIST 1.1. Plasma samples of these patients were collected before the administration of PD-1/PD-L1 inhibitors as baseline, and after every three cycles if the patients achieved partial response (PR) or complete response. Plasma from seven healthy individuals was also collected as normal control. Exosomes were prepared by ultracentrifugation followed by total RNA extraction, and exosome-derived miRNAs were profiled using small RNA next-generation sequencing followed by differential expression analysis.

Results

In order to identify biomarker for better response, all five patients who achieved PR and four patients with progressive disease (PD) at efficacy evaluation were included for differential expression analysis. Based on unsupervised hierarchical clustering, exosomal miRNA expression profile was significantly altered in patients with NSCLC compared with normal controls with a total of 155 differentially expressed exosomal miRNAs. Interestingly, hsa-miR-320d, hsa-miR-320c, and hsa-miR-320b were identified significantly upregulated in the PD groups compared with the PR group at baseline before the treatment. In addition, we identified that hsa-miR-125b-5p, a T-cell suppressor, showed a trend of increased expression in the PD group at baseline and was significantly downregulated in the post-treatment plasma exosomes compared with pre-treatment samples of the PR patients.

Conclusion

Patients with NSCLC represent unique plasma exosomal miRNA profiles. Hsa-miR-320d, hsa-miR-320c, and hsa-miR-320b were identified as potential biomarkers for predicting the efficacy of immunotherapy in advanced NSCLCs. When T-cell suppressor hsa-miR-125b-5p was downregulated during the treatment, the patients may obtain increased T-cell function and respond well to immunotherapy.

Extracellular microRNAs: key players to explore the outcomes of in vitro fertilization

BACKGROUND

MicroRNAs (miRNAs) are small RNA molecules that modulate post-transcriptional gene regulation. They are often used as promising non-invasive biomarkers for the early diagnosis of cancer. However, their roles in assisted reproduction are still unknown.

METHODS

This prospective study was designed to evaluate the expression profiles of seven extracellular miRNAs (miR-7-5p, miR-202-5p, miR-378-3p, miR-224, miR-320a, miR-212-3p, and miR-21-5p) in human follicular fluid (FF) to explore the outcomes of in vitro fertilization (IVF). Of 255 women, 145 were without polycystic ovary syndrome (PCOS), and their ovarian assets were normal (NOR), while 110 were with normo-androgenic PCOS.

RESULTS

The combination of six FF miRNAs expression profile discriminated between PCOS and NOR women with a sensitivity of 79.2% and a specificity of 87.32% (AUC = 0.881 [0.61; 0.92], p = 0.001). MiR-202-5p significantly had a lower abundance level, and miR-378-3p had a high abundance level in pooled FF samples from patients treated with human menopausal gonadotropin (hMG) than those treated with recombinant follicle-stimulating hormone (rFSH) (p < 0.001). Our results showed that miRNA-320a was significantly different in top-quality embryos versus non-top-quality embryos on day 3 in NOR patients with a sensitivity of 80% and specificity of 71%, (AUC = [0.753 (0.651; 0.855)], p = 0.001). For clinical pregnancy outcome prediction, FF miRNA-21 exhibited high sensitivity (74.8%) and specificity (83.7%) with the AUC value of 0.774 (0.682; 0.865).

CONCLUSION

Conclusively, our results provide evidence that miR-7-5p, miR-378-3p, miR-224, miR-212-3p were a differentially high expression in normo-androgenic PCOS patients than NOR patients. While miRNA-320a was significantly different in top-quality embryos versus non-top-quality embryos on day 3 (p = 0.001). The expression level of FF miR-212-3p was significantly related to the probability of embryos to develop into a high-quality blastocyst in patients with normal ovarian reserve.

miR-130b-3p is high-expressed in polycystic ovarian syndrome and promotes granulosa cell proliferation by targeting SMAD4

BACKGROUND

Being one of the most prevalent metabolic and endocrine disorders, Polycystic Ovary Syndrome (PCOS) has been proven to be associated with microRNA-130b-3p (miR-130b-3p). However, the exact role played by miR-130b-3p in the pathogenesis and progression of PCOS remains unknown. Thus, this article is focused on elucidating the function of miR-130b-3p in the pathogenesis of PCOS.

METHODS

The expression levels of miR-130b-3p and SMAD4 in tissues and cells responsible for the development of PCOS were determined by RT-qPCR and western blot. A miR-130b-3p mimic/inhibitor or si-SMAD4 were transfected into KGN cells. The cell viability was detected by CCK-8 and EDU methods. The activity of caspase-3 was measured by caspase-3 analysis. Subsequently, apoptosis and the cell cycle were measured via flow cytometry. The correlation between SMAD4 and miR-130b-3p was confirmed using an RNA pull-down assay and a dual luciferase reporter system assay.

RESULTS

MiR-130b-3p was upregulated in the KGN cells and ovarian granulosa cells (GCs) of PCOS patients. It was found that miR-130b-3p overexpression or SMAD4 silencing can promote KGN cell proliferation and positive EDU rates, induce S phase arrest, inhibit apoptosis and caspase-3 activity. On the other hand, miR-130b-3p inhibitors reduce KGN cell proliferation, inhibit apoptosis and reverse the effect of si-SMAD4.

CONCLUSION

MiR-130b-3p directly interacts with SMAD4 to induce KGN cell proliferation, inhibit apoptosis, suggesting that miR-130b-3p expression is positively correlated with the development of PCOS. This may serve as new evidence for the abnormal proliferation of GCs in PCOS.

MicroRNAs in amniotic fluid and maternal blood plasma associated with sex determination and early gonad differentiation in cattle†

We hypothesized that sexually dimorphic differences exist in the expression of miRNAs in amniotic fluid (AF) and maternal blood plasma (MP) in association with the process of sex determination and gonad differentiation in cattle. Amniotic fluid and MP were collected from six pregnant heifers (three carrying a single male and three a single female embryo) following slaughter on Day 39 postinsemination, coinciding with the peak of SRY expression. Samples (six AF and six MP) were profiled using an miRNA Serum/Plasma Focus PCR Panel. Differentially expressed (DE) miRNAs were identified in AF (n = 5) and associated MP (n = 56) of male vs. female embryos (P < 0.05). Functional analysis showed that inflammatory and immune response were among the 13 biological processes enriched by miRNAs DE in MP in the male group (FDR < 0.05), suggesting that these sex-dependent DE miRNAs may be implicated in modulating the receptivity of the dam to a male embryo. Further, we compared the downstream targets of the sex-dependent DE miRNAs detected in MP with genes previously identified as DE in male vs. female genital ridges. The analyses revealed potential targets that might be important during this developmental stage such as SHROOM2, DDX3Y, SOX9, SRY, PPP1CB, JARID2, USP9X, KDM6A, and EIF2S3. Results from this study highlight novel aspects of sex determination and embryo–maternal communication in cattle such as the potential role of miRNAs in gonad development as well as in the modulation of the receptivity of the dam to a male embryo.

lncRNA FDNCR promotes apoptosis of granulosa cells by targeting the miR-543-3p/DCN/TGF-β signaling pathway in Hu sheep

Long non-coding RNAs (lncRNAs) regulate the development of follicles and reproductive diseases, but the mechanisms by which lncRNAs regulate ovarian functions and fertility remain elusive. We profiled the expression of lncRNAs in ovarian tissues of Hu sheep with different prolificacy and identified 21,327 lncRNAs. Many of the lncRNAs were differentially expressed in different groups. We further characterized an lncRNA that was predominantly expressed in the ovaries of the low prolificacy Fec^B+ (LPB+) group and mainly present in granulosa cells (GCs), and the expression of this lncRNA decreased during follicular development, which we named follicular development-associated lncRNA (FDNCR). Next, we found that FDNCR directly binds miR-543-3p, and decorin (DCN) was identified as a target of miR-543-3p. FDNCR overexpression promoted GC apoptosis through increased expression of DCN, which could be attenuated by miR-543-3p. Furthermore, miR-543-3p increased and FDNCR reduced the expression of transforming growth factor-β (TGF-β) pathway-related genes, including TGF-β1 and inhibin beta A (INHBA), which were upregulated upon DCN silencing. Our results demonstrated that FDNCR sponges miR-543-3p in GCs and prevents miR-543-3p from binding to the DCN 3′ UTR, resulting in DCN transactivation and TGF-β pathway inhibition and promotion of GC apoptosis in Hu sheep. These findings provide insights into the mechanisms underlying prolificacy in sheep.

Deletion of lncRNA5512 has no effect on spermatogenesis and reproduction in mice

Long non-coding (lnc) RNAs are a series of RNAs longer than 200 nucleotides that do not code for protein products. Whole-genome expression profiles of lncRNAs suggest that they play important roles in spermatogenesis because they are particularly abundant in testes. However, most of their characteristics and functions remain unclear. The aim of this study was to define the function of lncRNA5512, which is abundant in spermatocytes and round spermatids, in mouse fertility invivo. To investigate this we generated lncRNA5512-knockout mice by clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) 9 technology. Knockout mice showed normal spermatogenesis and fertility, and had no detectable abnormalities. This indicates that lncRNA5512 does not affect mouse fertility despite its high expression in the testes. Its specific localisation in spermatocytes and round spermatids suggests that it could be a useful marker for the identification of spermatocytes and round spermatids in mouse testes.

miR-146a-5p Regulated Cell Proliferation and Apoptosis by Targeting SMAD3 and SMAD4

Background: microRNAs (miRNAs) are a small, endogenous non-coding RNAs that are involved in post-transcriptional gene regulation of many biological processes, including embryo implantation and placental development. In our previous study, miR-146a-5p was found expressed higher in the serum exosomes of pregnant sows than non-pregnant. The research on miR-146a-5p has been mainly related to human diseases, but there are few studies on its effects on the reproduction of sows in early pregnancy.

Objective: In this article, our motivation is to study the role of miR-146a-5p in the early pregnancy of sows on the cell proliferetion and apoptosis by targeting SMAD3 and SMAD4.

Methods: Bioinformatics software was used to identify the target genes of miR-146a-5p. The wild-type and mutant-type recombinant plasmids of dual-luciferase reporter with 3'-UTR of Smad3 or 3'-UTR of Smad4 were constructed, and co-transfected in porcine kidney cell (PK-15 cell) with miR-146a-5p mimic, mimic-NC(M-NC), inhibitor and inhibitor-NC(IN-NC), then dual-luciferase activity analysis, qRT-PCR and Western blot were performed to verify the target genes. After the transfection of BeWo choriocarcinoma cell (BeWo cell) with miR-146a-5p mimic, M-NC, inhibitor and IN-NC, the mRNA expression of Caspase-3, BAX and Bcl-2 was measured using qRT-PCR, and the cell proliferation was measured using CCK-8 kit.

Results: The luciferase, mRNA and protein expression of Smad3 in PK-15 cells treated by Smad3-3'-UTR-W co-transfected with miR-146a-5p mimic were significantly lower than that with miR-146a-5p M-NC, and the results of Smad4 were similar to Smad3, but the protein expression had a trend to lower in mimic group. The expression level of Bcl-2 in the miR-146a-5p mimic group was significantly lower than that in the miR-146a-5p M-NC group, but the expression pattern of Caspase-3 was just opposite. The mimic of miR-146a-5p reduced the proliferation of BeWo cells, however the inhibitor increased.

Conclusion: Smad3 and Smad4 are the direct target genes of miR-146a-5p. The expression of Smad3 and Smad4 were affected by the mimic and inhibitor of miR-146a-5p. miR-146a-5p affects cell apoptosis and proliferation by regulating their target genes. This study provided new data to understand the regulation mechanism of early pregnancy in sows.

Cellular, Extracellular and Extracellular Vesicular miRNA Profiles of Pre-Ovulatory Follicles Indicate Signaling Disturbances in Polycystic Ovaries

Cell-free RNAs have the potential to act as a means of gene expression regulation between cells and are therefore used as diagnostic markers describing the state of tissue environment. The origin and functions of such RNAs in human ovarian follicle, the environment of oocyte maturation, are unclear. The current study investigates the difference in the microRNA profiles of fertile women and polycystic ovary syndrome (PCOS) patients in three compartments from the same preovulatory follicle: mural granulosa cells (MGC), cell-free follicular fluid (FF), and extracellular vesicles (EV) of the FF by small RNA sequencing. In silico analysis was used for the prediction and over-representation of targeted pathways for the detected microRNAs. PCOS follicles were distinguished from normal tissue by the differential expression of 30 microRNAs in MGC and 10 microRNAs in FF (FDR < 0.1) that commonly regulate cytokine signaling pathways. The concentration of EV-s was higher in the FF of PCOS patients (p = 0.04) containing eight differentially expressed microRNAs (p < 0.05). In addition, we present the microRNA profiles of MGC, FF, and EV in the fertile follicle and demonstrate that microRNAs loaded into EVs target mRNAs of distinct signaling pathways in comparison to microRNAs in FF. To conclude, the three follicular compartments play distinct roles in the signaling disturbances associated with PCOS.

The role of microRNAs in ovarian function and the transition toward novel therapeutic strategies in fertility preservation: from bench to future clinical application

BACKGROUND

New therapeutic approaches in oncology have converted cancer from a certain death sentence to a chronic disease. However, there are still challenges to be overcome regarding the off-target toxicity of many of these treatments. Oncological therapies can lead to future infertility in women. Given this negative impact on long-term quality of life, fertility preservation is highly recommended. While gamete and ovarian tissue cryopreservation are the usual methods offered, new pharmacological-based options aiming to reduce ovarian damage during oncological treatment are very attractive. In this vein, advances in the field of transcriptomics and epigenomics have brought small noncoding RNAs, called microRNAs (miRNAs), into the spotlight in oncology. MicroRNAs also play a key role in follicle development as regulators of follicular growth, atresia and steroidogenesis. They are also involved in DNA damage repair responses and they can themselves be modulated during chemotherapy. For these reasons, miRNAs may be an interesting target to develop new protective therapies during oncological treatment. This review summarizes the physiological role of miRNAs in reproduction. Considering recently developed strategies based on miRNA therapy in oncology, we highlight their potential interest as a target in fertility preservation and propose future strategies to make the transition from bench to clinic.

OBJECTIVE AND RATIONALE

How can miRNA therapeutic approaches be used to develop new adjuvant protective therapies to reduce the ovarian damage caused by cytotoxic oncological treatments?

SEARCH METHODS

A systematic search of English language literature using PubMed and Google Scholar databases was performed through to 2019 describing the role of miRNAs in the ovary and their use for diagnosis and targeted therapy in oncology. Personal data illustrate miRNA therapeutic strategies to target the gonads and reduce chemotherapy-induced follicular damage.

OUTCOMES

This review outlines the importance of miRNAs as gene regulators and emphasizes the fact that insights in oncology can inspire new adjuvant strategies in the field of onco-fertility. Recent improvements in nanotechnology offer the opportunity for drug development using next-generation miRNA-nanocarriers.

WIDER IMPLICATIONS

Although there are still some barriers regarding the immunogenicity and toxicity of these treatments and there is still room for improvement concerning the specific delivery of miRNAs into the ovaries, we believe that, in the future, miRNAs can be developed as powerful and non-invasive tools for fertility preservation.

Integrated analysis of miRNA-mRNA interaction in ovaries of Turpan Black Sheep during follicular and luteal phases

To investigate the regulatory mechanism of the follicular-luteal phase transition in Turpan black sheep (Ovis aries), the genome-wide expression patterns of microRNAs (miRNAs) and genes were investigated in ovaries of six sheep (3 years and single lamb with 3 consecutive births) during follicular and luteal phases of the oestrous cycle. Bioinformatic analysis was used to screen potential miRNAs and genes related to Turpan black sheep ovarian function. RT-qPCR was used to validate the sequencing results. In total, we identified 139 known and 71 novel miRNAs in the two phases with miRNA-seq, and a total of 19 miRNAs were significantly differentially expressed, of which 7 were up-regulated and 12 were down-regulated in the follicular phase compared with luteal phase. A total of 150 genes were significantly differentially expressed, including 63 up-regulated and 87 down-regulated in the follicular phase compared with the luteal phase by RNA-seq data analysis. Those DEGs were significantly enriched in 103 GO terms and several KEGG pathways, including metabolic pathway, ovarian steroidogenesis, steroid hormone biosynthesis and oestrogen signalling pathway. In addition, we created a miRNA-mRNA regulatory network to further elucidate the mechanism of follicular-luteal transition. Finally, we identified key miRNAs and genes including miR-143, miR-99a, miR-150, miR-27a, miR-125b, STAR, STAT1, which might play crucial roles in reproductive hormone biosynthesis and follicular development. The miRNA-mRNA interactive network clearly illustrates molecular basis involving in follicular-luteal transition.

High Expression of miR-204 in Chicken Atrophic Ovaries Promotes Granulosa Cell Apoptosis and Inhibits Autophagy

Chicken atrophic ovaries have decreased volume and are indicative of ovarian failure, presence of a tumor, or interrupted ovarian blood supply. Ovarian tumor is accompanied by an increase in follicular atresia, granulosa cell (GC) apoptosis, and autophagy. In a previous study, we found using high throughput sequencing that miR-204 is highly expressed in chicken atrophic ovaries. Thus, in the present study, we further investigated its function in GC apoptosis and autophagy. We found that overexpression of miR-204 reduced mRNA and protein levels of proliferation-related genes and increased apoptosis-related genes. Cell counting kit-8 (CCK-8), 5-ethynyl-2-deoxyuridine (EdU), and flow cytometry assays revealed that miR-204 inhibited GC proliferation and promoted apoptosis. Furthermore, we confirmed with reporter gene assays that Forkhead box K2 (FOXK2) was directly targeted by miR-204. FOXK2, as a downstream regulator of phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signal pathways, promoted GC proliferation and inhibited apoptosis. Subsequently, we observed that miR-204 was involved in GC autophagy by targeting Transient Receptor Potential Melastatin 3 (TRPM3). The luciferase activities of the two binding sites of TRPM3 were decreased in response to treatment with a miR-204 mimic, and the autophagic flux was increased after miR-204 inhibition. However, overexpression of miR-204 had opposite results in autophagosomes and autolysosomes. miR-204 inhibits GC autophagy by suppressing the protein expression of TRPM3/AMP-activated protein kinase (AMPK)/ULK signaling pathway components. Inhibition of miR-204 enhanced autophagy by accumulating and degrading the protein levels of LC3-II (Microtubule Associated Protein Light Chain 3B) and p62 (Protein of 62 kDa), respectively, whereas miR-204 overexpression was associated with contrary results. Immunofluorescence staining showed that there was a significant reduction in the fluorescent intensity of LC3B, whereas p62 protein was increased after TRPM3 silencing. Collectively, our results indicate that miR-204 is highly expressed in chicken atrophic ovaries, which promotes GC apoptosis via repressing FOXK2 through the PI3K/AKT/mTOR pathway and inhibits autophagy by impeding the TRPM3/AMPK/ULK pathway.

MicroRNA-127-5p impairs function of granulosa cells via HMGB2 gene in premature ovarian insufficiency

Distinct microRNA (miRNA) profiles have been reported in premature ovarian insufficiency (POI), but their functional relevance in POI is not yet clearly stated. In this study, aberrant expressions of miR-127-5p and high mobility group box 2 (HMGB2) were observed by microarrays in granulosa cells (GCs) from biochemical POI (bPOI) women and further confirmed by a quantitative reverse-transcription polymerase chain reaction. Immortalized human granulosa cell line and mouse primary ovarian GCs were used for functional validation. Orthotopic mouse model was established to examine the role of miR-127-5p in vivo. Finally, the expression of miR-127-5p was measured in the plasma of bPOI women. The receiver operating characteristic curve analysis was performed to determine the indicative role of miR-127-5p for ovarian reserve. Results showed the upregulation of miR-127-5p was identified in GCs from bPOI patients. It inhibited GCs proliferation and impaired DNA damage repair capacity through targeting HMGB2, which was significantly downregulated in GCs from the same cohort of cases. miR-127-5p was confirmed to attenuate DNA repair capability via HMGB2 in mouse ovary in vivo. Intriguingly, the upexpression of miR-127-5p was also detected in plasma of bPOI individuals, suggesting that miR-127-5p could be a promising indicator for bPOI. Taken together, our results discovered the deleterious effects of miR-127-5p on GCs function and its predictive value in POI process. The target gene HMGB2 could be considered as a new candidate for POI. This study highlights the importance of DNA repair capacity for ovarian function and sheds light on the epigenetic mechanism in the pathogenicity of POI.

Effects of miR-101-3p on goat granulosa cells in vitro and ovarian development in vivo via STC1

Background

MiRNAs act as pivotal post-transcriptional gene mediators in the regulation of diverse biological processes, including proliferation, development and apoptosis. Our previous study has showed that miR-101-3p is differentially expressed in dairy goat ovaries compared single with multiple litters. The objective of this research was to explore the potential function and molecular mechanism of miR-101-3p via its target STC1 in goat ovarian growth and development.

Results

cDNA libraries were constructed using goat granulosa cells transfected with miR-101-3p mimics and negative control by RNA-sequencing. In total, 142 differentially expressed unigenes (DEGs) were detected between two libraries, including 78 down-regulated and 64 up-regulated genes. GO and KEGG enrichment analysis showed the potential impacts of DEGs on ovarian development. STC1 was singled out from DEGs for further research owing to it regulates reproductive-related processes. In vitro, bioinformatics analysis and 3′-UTR assays confirmed that STC1 was a target of miR-101-3p. ELISA was performed to detect the estrogen (E2) and progesterone (P4) levels. CCK8, EdU and flow cytometry assays were performed to detect the proliferation and apoptosis of granulosa cells. Results showed that miR-101-3p regulated STAR, CYP19A1, CYP11A1 and 3β-HSD steroid hormone synthesis-associated genes by STC1 depletion, thus promoted E2 and P4 secretions. MiR-101-3p also affected the key protein PI3K, PTEN, AKT and mTOR in PI3K-AKT pathway by STC1, thereby suppressing proliferation and promoting apoptosis of granulosa cells. In vivo, the distribution and expression levels of miR-101-3p in mouse ovaries were determined through fluorescence in situ hybridisation (FISH). Immunohistochemistry results showed that STC1 expression was suppressed in mouse ovaries in miR-101-3p-agonist and siRNA-STC1 groups. Small and stunted ovarian fragments, decreased numbers of follicles at diverse stages were observed using Hematoxylin-eosin (HE) staining, thereby showing unusual ovarian development after miR-101-3p overexpression or STC1 depletion. Inhibition of miR-101-3p manifested opposite results.

Conclusions

Taken together, our results demonstrated a regulatory mechanism of miR-101-3p via STC1 in goat granulosa cells, and offered the first in vivo example of miR-101-3p and STC1 functions required for ovarian development.

MiR-29 regulates the function of goat granulosa cell by targeting PTX3 via the PI3K/AKT/mTOR and Erk1/2 signaling pathways

PTX3, a member of the pentraxin protein family, plays important roles in ovulation as a marker of cumulus cell-oocyte complex expansion. However, the expression and function of PTX3 in goat ovarian GCs remain unclear. We isolated GCs from small and large follicles and found that PTX3 expression was significantly decreased and miR-29 mRNA expression was significantly increased during the growth of antral follicles. MiR-29 decreased PTX3 expression by targeting its 3' untranslated. Furthermore, miR-29 promoted GC proliferation, suppressed steroidogenesis and apoptosis by targeting PTX3 via the activation of the PI3K/AKT/mTOR and Erk1/2 signaling pathways. Treatment with inhibitors also verified these results. Meanwhile, we found that PI3K/AKT/mTOR and Erk1/2 signaling pathways had different role in secretion of E2 and P4 by regulating differently various steroidogenic enzyme (CYP19A1, CYP11A1, StAR and HSD3B) expression. These outcomes indicate the potential role of PTX3 in goat follicular growth and atresia.

miR-4463 regulates aromatase expression and activity for 17β-estradiol synthesis in response to follicle-stimulating hormone

Objective

The aim of this study was to investigate microRNAs (miRNAs) related to follicle-stimulating hormone (FSH) responsiveness using miRNA microarrays and to identify their target genes to determine the molecular regulatory pathways involved in FSH signaling in KGN cells.

Methods

To change the cellular responsiveness to FSH, KGN cells were treated with FSH receptor (FSHR)-specific small interfering RNA (siRNA) followed by FSH. miRNA expression profiles were determined through miRNA microarray analysis. Potential target genes of selected miRNAs were predicted using bioinformatics tools, and their regulatory function was confirmed in KGN cells.

Results

We found that six miRNAs (miR-1261, miR-130a-3p, miR-329-3p, miR-185-5p, miR-144-5p and miR-4463) were differentially expressed after FSHR siRNA treatment in KGN cells. Through a bioinformatics analysis, we showed that these miRNAs were predicted to regulate a large number of genes, which we narrowed down to cytochrome P450 family 19 subfamily A member 1 (CYP19A1) and estrogen receptor alpha (ESR1) as the main targets for miR-4463. Functional analysis revealed that miR-4463 is a regulatory factor for aromatase expression and function in KGN cells.

Conclusion

In this study, we identified differentially expressed miRNAs related to FSH responsiveness. In particular, upregulation of miR-4463 expression by FSHR deficiency in human granulosa cells impaired 17β-estradiol synthesis by targeting CYP19A1 and ESR1. Therefore, our data might provide novel candidates for molecular biomarkers for use in research into poor responders.

A Preliminary Study on the Characteristics of microRNAs in Ovarian Stroma and Follicles of Chuanzhong Black Goat during Estrus

microRNAs (miRNAs) play a significant role in ovarian follicular maturity, but miRNA expression patterns in ovarian stroma (OS), large follicles (LF), and small follicles (SF) have been rarely explored. We herein aimed to identify miRNAs, their target genes and signaling pathways, as well as their interaction networks in OS, LF, and SF of Chuanzhong black goats at the estrus phase using small RNA-sequencing. We found that the miRNA expression profiles of LF and SF were more similar than those of OS—32, 16, and 29 differentially expressed miRNAs were identified in OS vs. LF, OS vs. SF, and LF vs. SF, respectively. Analyses of functional enrichment and the miRNA-targeted gene interaction network suggested that miR-182 (SMC3), miR-122 (SGO1), and miR-206 (AURKA) were involved in ovarian organogenesis and hormone secretion by oocyte meiosis. Furthermore, miR-202-5p (EREG) and miR-485-3p (FLT3) were involved in follicular maturation through the MAPK signaling pathway, and miR-2404 (BMP7 and CDKN1C) played a key role in follicular development through the TGF-β signaling pathway and cell cycle; nevertheless, further research is warranted. To our knowledge, this is the first study to investigate miRNA expression patterns in OS, LF, and SF of Chuanzhong black goats during estrus. Our findings provide a theoretical basis to elucidate the role of miRNAs in follicular maturation. These key miRNAs might provide candidate biomarkers for the diagnosis of follicular maturation and will assist in developing new therapeutic targets for female goat infertility.

miRNAs as a novel clinical biomarker and therapeutic targets in polycystic ovary syndrome (PCOS): A review

Polycystic ovary syndrome (PCOS) is the most prevalent endocrine disorder in females of the reproductive age. PCOS is commonly manifested as ovulatory dysfunction, clinical and biochemical excess androgen level, and polycystic ovaries. Metabolic sequelae associated with PCOS, including insulin resistance (IR), type 2 diabetes (T2DM), obesity and increased cardiometabolic risk. The underlying pathology of PCOS is not fully understood with various genetic and environmental factors have been proposed. MicroRNAs (miRNAs), are endogenously produced, small non-coding, single-stranded RNAs that capable of regulating gene expression at the post-transcriptional level. Altered miRNAs expression has been associated with various disorders, including T2DM, IR, lipid disorder, infertility, atherosclerosis, endometriosis, and cancer. Given that PCOS also present with similar features, there is an increasing interest to investigate the role of miRNAs in the diagnosis and management of PCOS. In recent years, studies have demonstrated that miRNAs are present in various body fluids, including follicular fluid of women with PCOS. Therefore, it may act as a potential biomarker and could serve as a novel therapeutic target for the diagnosis and treatment of PCOS. This review aims to summarise the up to date research on the relation between miRNAs and PCOS and explore its potential role in the diagnosis and the management of PCOS.

MiR224-5p Inhibitor Restrains Neuronal Apoptosis by Targeting NR4A1 in the Oxygen-Glucose Deprivation (OGD) Model

This study was designed to investigate the molecular mechanism of stroke and to explore the effect of miR-224-5p in hypoxic cortical neurons. Firstly, we established a middle cerebral artery occlusion (MCAO) model with Sprague–Dawley rats. Triphenyltetrazolium chloride (TTC) staining showed the brain infarction of an MCAO rat. Longa scores of rats were significantly increased in 12th, 24th, and 48th hours after MCAO. Then, we found that miR-224-5p was increased after MCAO in rats by qRT-PCR. In order to investigate the effect of miR-224-5p in hypoxic neurons, we established an oxygen-glucose deprivation (OGD) model with cortical neurons. MiR-224-5p was also upregulated in neurons after OGD by qRT-PCR. After transfection of the miR-224-5p inhibitor, the number of neurons in the anti-miR-224-5p group significantly increased (P < 0.01) in comparison to the anti-NC group. Furthermore, Tuj1⁺ (neuronal marker) staining and TUNEL assay (to detect apoptotic cells) were performed in neurons. The survival of neurons in the anti-miR-224-5p group was significantly improved (P < 0.01), while the apoptosis of neurons in the anti-miR-224-5p group was significantly decreased (P < 0.01), when compared with that of the anti-NC group. In addition, we predicted that potential target genes of miR-224-5p were nuclear receptor subfamily 4 group A member 1 (NR4A1), interleukin 1 receptor antagonist (IL1RN), and ring finger protein 38 (RNF38) with bioinformatics databases, such as TargetScan, miRDB, miRmap, and miRanda. The result of qRT-PCR confirmed that NR4A1 was significantly decreased after hypoxic injury (P < 0.01). Meanwhile, luciferase reporter’s assay indicated that NR4A1 was the direct target of miR-224-5p. Compared with the anti-miR-224-5p + siNC group, the number of cortical neurons and the length of the neuron axon in the anti-miR-224-5p + si-NR4A1 group were significantly decreased (P < 0.01), and the number of neuronal apoptosis in the anti-miR-224-5p + si-NR4A1 group was increased (P < 0.01). In conclusion, miR-224-5p played a crucial role in hypoxic neuron injury through NR4A1, which might be an important regulatory mechanism in OGD injury of neurons.

MiRNA-155 regulates cumulus cells function, oocyte maturation, and blastocyst formation

Numerous oocytes are retrieved during in vitro fertilization from patients with polycystic ovary syndrome (PCOS). The poor quality of these oocytes leads to lower fertilization and decreases in cleavage and implantation. MiR-155 is one of the microRNA (miRNA) that is increased in serum and granulosa cells of PCOS patients. In this study, we investigate the effects of miR-155 expression and its target genes on oocyte maturation and embryo development. We used the calcium phosphate protocol to transfect vectors that contained miR-155 or miR-off 155 and alone eGFP into cumulus oophorus complex (COCs) of B6D2F1 female mice for in vitro maturation. Cumulus expansion, nuclear, and cytoplasmic maturation, as well as cleavage rates were determined in groups transfected and compared with the control groups. Quantitative real-time polymerase chain reaction was performed to analyze expression levels of miR-155 and the target genes in the cumulus cells, oocytes, and blastocysts. MiR-155 overexpression in COCs suppressed cumulus expansion, oocyte maturation, and inhibition of endogenous miR-155 by miR-off 155 improved cumulus expansion and oocyte maturation by downregulation and expression increase of the Smad2 and Bcl2 genes. On the other hand, overexpression and downregulation of miR-155 in the COCs led to increase and decrease in cleavage rates by changes in expressions of the Mecp2, Jarid2, and Notch1 genes, respectively (P &lt; 0.05). These results suggested that miR-155 overexpression in granulosa cells of PCOS patients can negatively affect nuclear and cytoplasmic maturation, but this miRNA expression has a positive impact on embryo development.

MiR-423-5p may regulate ovarian response to ovulation induction via CSF1

BACKGROUND

We have previously shown that hsa-miR-423-5p expression in ovarian granulosa cells is decreased in high ovarian response populations. The objective of the present study was to find the target gene and mechanism for miR-423-5p involved in ovarian response regulation.

METHODS

(a) TargetScan was used to predict the target gene of hsa-miR-423-5p. (b) A model for hsa-miR-423-5p overexpression or inhibition was constructed by transfecting KGN cells with lentivirus. CSF1 mRNA and protein expression and luciferase activity were measured. (c) The cell cycles of control and lentivirus treated KGN cells were analyzed. Western blot was used to measure the expression of CDKN1A in KGN cells. (d) The concentration of E₂ in KGN cell culture medium were measured.

RESULTS

(a) TargetScan revealed that the 3' un-translated region of CSF1 matched 11 bases at the 5' end of miR-423-5p, making it a likely target gene. (b) Overexpression or inhibition of miR-423-5p were associated with respective decreases or increases in CSF1 expression (both mRNA and protein) (p < 0.05) and luciferase activity (p < 0.05). (c) When miR-423-5p expression increased, the number of G0/G1 phase cells and the expression of CDKN1A protein increased while estradiol concentrations in the cell culture solution decreased (p < 0.05). However, when miR-423-5p expression decreased, the number of S phase cells increased and E2 concentrations increased while the expression of CDKN1A protein decreased (p < 0.05).

CONCLUSIONS

Colony stimulating factor 1 is a target gene of miR-423-5p and that it may regulate ovarian response to ovulation induction by affecting granulosa cells proliferation and estrogen secretion.

Transactivation of miR-202-5p by Steroidogenic Factor 1 (SF1) Induces Apoptosis in Goat Granulosa Cells by Targeting TGFβR2

MicroRNAs play key roles during ovary development, with emerging evidence suggesting that miR-202-5p is specifically expressed in female animal gonads. Granulosa cells (GCs) are somatic cells that are closely related to the development of female gametes in mammalian ovaries. However, the biological roles of miR-202-5p in GCs remain unknown. Here, we show that miR-202-5p is specifically expressed in GCs and accumulates in extracellular vesicles (EVs) from large growth follicles in goat ovaries. In vitro assays showed that miR-202-5p induced apoptosis and suppressed the proliferation of goat GCs. We further revealed that miR-202-5p is a functional miRNA that targets the transforming growth factor-beta type II receptor (TGFβR2). MiR-202-5p attenuated TGF-β/SMAD signaling through the degradation of TGFβR2 at both the mRNA and protein level, decreasing p-SMAD3 levels in GCs. Moreover, we verified that steroidogenic factor 1 (SF1) is a transcriptional factor that binds to the promoters of miR-202 and cytochrome P450 family 19 subfamily A member 1 (CYP19A1) through luciferase reporter and chromatin immunoprecipitation (ChIP) assays. That contributed to positive correlation between miR-202-5p and CYP19A1 expression and estradiol (E2) release. Furthermore, SF1 repressed TGFβR2 and p-SMAD3 levels in GCs through the transactivation of miR-202-5p. Taken together, these results suggest a mechanism by which miR-202-5p regulates canonical TGF-β/SMAD signaling through targeting TGFβR2 in GCs. This provides insight into the transcriptional regulation of miR-202 and CYP19A1 during goat ovarian follicular development.

The role of miRNAs in regulating adrenal and gonadal steroidogenesis

miRNAs are endogenous noncoding single-stranded small RNAs of ~22 nucleotides in length that post-transcriptionally repress the expression of their various target genes. They contribute to the regulation of a variety of physiologic processes including embryonic development, differentiation and proliferation, apoptosis, metabolism, hemostasis and inflammation. In addition, aberrant miRNA expression is implicated in the pathogenesis of numerous diseases including cancer, hepatitis, cardiovascular diseases and metabolic diseases. Steroid hormones regulate virtually every aspect of metabolism, and acute and chronic steroid hormone biosynthesis is primarily regulated by tissue-specific trophic hormones involving transcriptional and translational events. In addition, it is becoming increasingly clear that steroidogenic pathways are also subject to post-transcriptional and post-translational regulations including processes such as phosphorylation/dephosphorylation, protein‒protein interactions and regulation by specific miRNAs, although the latter is in its infancy state. Here, we summarize the recent advances in miRNA-mediated regulation of steroidogenesis with emphasis on adrenal and gonadal steroidogenesis.

miR-181a promotes porcine granulosa cell apoptosis by targeting TGFBR1 via the activin signaling pathway

Activin/Smad3 signaling plays a pivotal role in follicle development and atresia. However, the precise mechanisms underlying this process are not yet fully understood. Herein, we identified miR-181a as a central component of activin/Smad3-mediated follicle atresia. miR-181a was strikingly upregulated in porcine atretic follicles, which induced the apoptosis of porcine granulosa cells (GCs) in vitro. Furthermore, the transforming growth factor-β type 1 receptor (TGFBR1) was confirmed as a direct target of miR-181a by bioinformatics analysis and luciferase assays. Transfection with an miR-181a agomir repressed the TGFBR1 mRNA and protein levels. In addition, TGFBR1 overexpression repressed GC apoptosis, whereas TGFBR1 inhibition promoted GC apoptosis. miR-181a overexpression downregulated the phosphorylation of Smad3 and blocked the activation of TGF-β signaling. Moreover, activin A downregulated miR-181a expression and upregulated the TGFBR1 and p-Smad3 protein levels. Collectively, these data suggest that miR-181a regulates porcine GC apoptosis by targeting TGFBR1 via the activin signaling pathway.

Reporting on the Role of miRNAs and Affected Pathways on the Molecular Backbone of Ovarian Insufficiency: A Systematic Review and Critical Analysis Mapping of Future Research

Ovarian insufficiency is identified as a perplexing entity in the long list of pathologies impairing fertility dynamics. The three distinct classifications of ovarian insufficiency are poor ovarian response, premature ovarian insufficiency/failure, and advanced maternal age, sharing the common denominator of deteriorated ovarian reserve. Despite efforts to define clear lines among the three, the vast heterogeneity and overlap of clinical characteristics renders their diagnosis and management challenging. Lack of a consensus has prompted an empirically based management coupled by uncertainty from the clinicians' perspective. Profiling of patients in the era of precision medicine seems to be the way forward, while the necessity for a novel approach is underlined. Implicating miRNAs in the quest for patient profiling is promising in light of their fundamental role in cellular and gene expression regulation. To this end, the current study sets out to explore and compare the three pathophysiologies-from a molecular point of view-in order to enable profiling of patients in the context of in vitro fertilization treatment and enrich the data required to practice individualized medicine. Following a systematic investigation of literature, data referring to miRNAs were collected for each patient category based on five included studies. miRNA-target pairs were retrieved from the DIANA-TarBase repository and microT-CDS. Gene and miRNA annotations were derived from Ensembl and miRbase. A subsequent gene-set enrichment analysis of miRNA targets was performed for each category separately. A literature review on the most crucial of the detected pathways was performed to reveal their relevance to fertility deterioration. Results supported that all three pathophysiologies share a common ground regarding the affected pathways, naturally attributed to the common denominator of ovarian insufficiency. As evidenced, miRNAs could be employed to explore the fine lines and diverse nature of pathophysiology since they constitute invaluable biomarkers. Interestingly, it is the differentiation through miRNAs and not through the molecular affected pathways that corresponds to the three distinctive categories. Alarming discrepancies among publications were revealed, pertaining to employment of empirical and arbitrary criteria in categorizing the patients. Following bioinformatic analysis, the final step of the current study consisted of a critical analysis of the molecular data sourced, providing a clear and unique insight into the physiological mechanisms involved. It is our intention to contribute to mapping future research dedicated to ovarian insufficiency and to help researchers navigate the overwhelming information published in molecular studies.